A marker and a dye are mixed in a fuel to be used for classification of oil types of liquid fuel products, taxable products and tax-free products, and for prevention of illegal incorporation and manufacture all over the world. The marker is diluted in the oil products at a low concentration (10 to 200 mg/kg) in order not to change physical properties of the fuel, and has a stable structure in which chemical reactions are not generated by a fuel component itself.
The marker used in a petrochemical industry is largely divided into a visible marker, a covert marker, and a chemical marker. The visible marker is advantageous in view of price, but is disadvantageous in that it is easy to be illegally removed, and the covert marker is difficult to be illegally removed, but has disadvantages in that it requires a high-priced specific analysis equipment, and the price is expensive. Accordingly, a number of countries largely use the chemical marker having the advantage while compensating the disadvantages of both of the markers. The chemical marker generates the chemical reaction with a developer to visualize a specific color, and is used to classify the oil types and to prevent the illegal incorporation into high-priced products or into taxable products by mixing the chemical marker with specific oil (non-taxable products or low-priced oil types, etc.) at a predetermined ratio. Accordingly, in order to determine whether the illegal incorporation occurs, the developer has added a marker that shows up as a color, and whether the marker is present is determined by using a UV-Vis spectrophotometer.
Meanwhile, there are a number of cases that low-priced oil products are illegally mixed with other high-priced oil products and distributed by fake oil manufacturers. In particular, kerosene is illegally mixed with automotive diesel to manufacture fake diesel. Now, the chemical marker included in the kerosene has a disadvantage in that it is easy to be illegally removed, which is difficult to exactly determine whether other products are illegally mixed with normal oil products. Cases where the kerosene is illegally mixed with the diesel to be distributed by using this disadvantage, have arisen. In addition, the manufactured fake diesel has low quality standards as compared to normal diesel, and reduced output in high engine revolution by 2 to 3%. In addition, when measuring exhaust gas, emissions such as carbon monoxide (CO), nitrogen oxide (NOx), unburned hydrocarbon (THC), etc., are increased by up to about 20%, air pollution is induced, and at the same time, a large-scale accident resulting from breakdown of car components such as a fuel injector, a fuel pump, etc., due to a decrease in lubricity may be caused.
That is, the fake oil manufactured by the illegal mixing of fuel oil causes a national tax evasion problem, a safety problem due to vehicle breakdown by owners, and an environmental pollution problem resulting from an increase in emission gases, etc. In order to prevent the illegal mixing of the fuel oil, the marker corresponding to oil types is incorporated to be distributed, but the conventionally developed marker for fuel has most of the artificial molecules that are not included in the fuel component, the molecule having large molecular weight and polar characteristic as compared to molecules forming the fuel, such that the marker in the fuel may be illegally removed by various removing methods suitable for properties of the marker.
Therefore, a novel form of a marker for oil products which is not easily removable by physical and chemical methods and is able to easily determine whether illegal mixing of the oil products occurs, has been demanded.